Vallisneria americana Michx.

TAPEGRASS; AMERICAN EELGRASS

**

**

Vallisneria neotropicalis is here included as a synonym of V. americana (Lowden 1982). Whether or not the two are distinct is presently unclear as little is known of the geographic limits and morphological variation in the Americas. Populations of Vallisneria are concentrated in the Great Lakes region, Gulf Coast, and Pacific Northwest, with scattered occurrences between them. DNA sequences of ITS loci have shown they together form a monophyletic clade (Les et al. 2008). Within this clade, the four samples of northern V. americana (from Connecticut [2], Minnesota, and New Jersey) formed a strongly supported group sister to a weakly supported group composed of two samples of putative V. neotropicalis (from Florida and cultivation of unknown provenance) and an unidentified umbellate specimen from Texas (Les et al. 2008).

Native OBL (NWPL)